I don't understand what is all about. If U know the meaning and importance of PMs You've got an answer. I'm using PMs and PNF patterns at Cardio ICU. Our patients sometimes "stay" for a couple of months with us. Coma, stroke, long-term gone and other complications.
We treat them twice a day for at least 30 min. We use also positionig with change after 2h, but that is nursing stuff duty. We don't use splints 'couse it carries to much risk
We prefer to prevent not to get tired later... (and our bedsores prevention is working very good)

I personally prefer to use positioning to maintain joint ROM and splint (usually Feet/ ankles) when ROM starts to decrease

but why it starts to decrease? maybe because of lack of PMs ??
I know that there can appear periarticular calcifications, but if we work hard, decreasing ROM can be slower...